On Thu, Oct 29, 2020 at 03:29:17PM +0800, Chao Yu wrote:
> > +static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long
> > arg)
> > +{
> > + struct inode *inode = file_inode(filp);
> > + struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> > + struct f2fs_comp_option option;
> > + int ret = 0;
> > +
> > + if (!f2fs_sb_has_compression(sbi))
> > + return -EOPNOTSUPP;
> > +
> > + if (!(filp->f_mode & FMODE_WRITE))
> > + return -EBADF;
> > +
> > + if (copy_from_user(&option, (struct f2fs_comp_option __user *)arg,
> > + sizeof(option)))
> > + return -EFAULT;
> > +
> > + if (!f2fs_compressed_file(inode) ||
> > + option.log_cluster_size < MIN_COMPRESS_LOG_SIZE ||
> > + option.log_cluster_size > MAX_COMPRESS_LOG_SIZE ||
> > + option.algorithm >= COMPRESS_MAX)
> > + return -EINVAL;
> > +
> > + file_start_write(filp);
> > + inode_lock(inode);
> > +
> > + if (f2fs_is_mmap_file(inode) || get_dirty_pages(inode)) {
> > + ret = -EBUSY;
> > + goto out;
> > + }
> > +
> > + if (inode->i_size != 0) {
> > + ret = -EFBIG;
> > + goto out;
> > + }
>
> Hmm...
>
> Shouldn't it be:
>
> if (algorithm >= COMPRESS_MAX) {
> ret = -ENOPKG;
> goto out;
> }
>
> if (!f2fs_cops[algorithm])
> f2fs_warn(...);
Note that my intent with recommending ENOPKG was for it to be returned in the
!f2fs_cops[algorithm] case, similar to how opening an encrypted file when the
encryption algorithm is recognized but not supported by the kernel returns
ENOPKG. For a truly unrecognized algorithm (algorithm >= COMPRESS_MAX), EINVAL
would probably be more appropriate. So if !f2fs_cops[algorithm] is now allowed,
then ENOPKG should no longer be among the error codes this ioctl returns.
- Eric
